Next generation cellular communication standards beyond 5G are planned to schedule non-orthogonal sub-frames, referred to as numerologies, in adjacent bands. Numerologies, in their current definition, refer to cyclic prefix (CP)-orthogonal frequency division multiplexing (OFDM) (CP-OFDM) waveform using different subcarrier spacings, and at some extents, using assorted CP rates. Different numerologies interfere with one-another, and adjacent channel interference (ACI) becomes the factor limiting data rates if the interfering block outpowers the desired block at the intended receiver. Receiver windowing reduces ACI absorption, and various methods are extensively studied in the literature to reduce energy absorbed from sidebands.
Contemporary orthogonal frequency division multiplexing (OFDM) receiver windowing algorithms used to mitigate adjacent channel interference (ACI) require cyclic extensions that are not disturbed by multipath interference. Such algorithms are unusable unless adopted by a new backward incompatible standard that incorporates such extensions. Additional temporal extensions lessen throughput by reducing effective symbol rate and specifically endanger high mobility wireless communication by pushing the period between pilots beyond the coherence time of the channel, requiring increased pilot overhead and resulting in inter-carrier interference (ICI). Additionally, conventional algorithms do not perform as well with limited extensions.
Accordingly, what is needed in the art is a receiver that improves the capacity of the system that does not require modifications at the transmitter and that results in structures that are orthogonal to, and support, legacy devices. However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in the field of this invention how the shortcomings of the prior art could be overcome.
The present invention may address one or more of the problems and deficiencies of the prior art discussed above. However, it is contemplated that the invention may prove useful in addressing other problems and deficiencies in a number of technical areas. Therefore, the claimed invention should not necessarily be construed as limited to addressing any of the particular problems or deficiencies discussed herein.
All referenced publications are incorporated herein by reference in their entirety. Furthermore, where a definition or use of a term in a reference, which is incorporated by reference herein, is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
While certain aspects of conventional technologies have been discussed to facilitate disclosure of the invention, Applicants in no way disclaim these technical aspects, and it is contemplated that the claimed invention may encompass one or more of the conventional technical aspects discussed herein.
In this specification, where a document, act or item of knowledge is referred to or discussed, this reference or discussion is not an admission that the document, act or item of knowledge or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions; or is known to be relevant to an attempt to solve any problem with which this specification is concerned.